Handheld biometric sensor for mobile devices

Abstract

A system and method comprises structure for receiving in a handheld device biometric or environmental data from the vicinity of the handheld device. The system may include a handheld mobile device such as a cellular telephone, or that device and a separate mechanical housing configured be held in a hand of a user and to clamp to or contain the handheld device. The system may include a specialized radar unit and be designed to analyze radar signals to provide a signal indicative of time varying arterial blood pressure. The mechanical housing may include a receiver designed to receive a biometric or environmental signal and to wirelessly transmit a corresponding signal to the handheld device when clamped to the handheld device.

1 . A system for determining arterial blood pressure of a user as a function of time, comprising:
 a handheld structure comprising at least one of: (1) a handheld device configured to be held in one hand of a person comprising a cellular telephone transceiver and human interface; and (2) a handheld mechanical housing configured to be held in one hand of the person, and designed to removably mechanically attach or clamp onto a handheld device;   a frequency controlled oscillator to generate Radio Frequency (RF) signals;   at least one antenna configured to transmit the RF signals generated by the frequency controlled oscillator and configured to receive RF signals which are reflections of the transmitted RF signals;   a mixer configured to mix at least one of the transmitted RF signals with at least one of the reflected RF signals to generate a modified signal;   an analog-to-digital converter configured to convert the modified signal into digital data thereby providing a digital representation of said modified signal;   at least one processor for processing digital data;   wherein said handheld structure contains said frequency controlled oscillator; said at least one antenna; and said mixer; said analog-to-digital converter, and said at least one processor; and   wherein said system is configured to use said digital representation of said modified signal and a model relating said modified signal to arterial blood pressure, to generate an arterial blood pressure signal indicating arterial blood pressure of the user as a function of time;   said at least one antenna defines a slot;   a feed line in the form of a conductive layer coupling said the RF signals generated by the frequency controlled oscillator to said antenna;   wherein said frequency controlled oscillator is controlled to generate said Radio Frequency (RF) signals in pulses at a repetition rate, and said repetition rate is sufficiently above the heart rate to provide reflection signal data points allowing curve fitting the reflection signal data to form a useful approximation for periodic variations in artery diameter at the periodicity of the heart rate   wherein said frequency controlled oscillator is controlled to generate said Radio Frequency (RF) signals in a frequency range between 3.1 and 10.6 GHz and with a subband of bandwidth of at least 500 MHz;   wherein said RF signals generated by the frequency controlled oscillator have peak power between 1 uW and 100 mW peak, and average power between 1 uW (microWatt) and 10 mW (milliWatt); and   a battery, wherein said battery provides power to said frequency controlled oscillator.   
     
     
         2 . The system of  claim 1  wherein said handheld device contains said frequency controlled oscillator, said at least one antenna; and said mixer; said analog-to-digital converter; and said at least one processor. 
     
     
         3 . The system of  claim 1 , wherein said oscillator is configured to generate signals having a bandwidth of at least 3 GHz in a frequency range between 3.0 GHz to 10.7 GHz. 
     
     
         4 . The system of  claim 1 , wherein said mixer comprises a single mixer; and wherein said mixer is configured to couple said frequency controlled oscillator to said at least one antenna. 
     
     
         5 . A system for determining arterial blood pressure of a user as a function of time, comprising:
 a handheld structure comprising at least one of: (1) a handheld device configured to be held in one hand of a person comprising a cellular telephone transceiver and human interface; and (2) a handheld mechanical housing configured to be held in one hand of the person, and designed to removably mechanically attach or clamp onto a handheld device;   a frequency controlled oscillator to generate Radio Frequency (RF) signals;   at least one antenna configured to transmit the RF signals generated by the frequency controlled oscillator and configured to receive RF signals which are reflections of the transmitted RF signals;   a mixer configured to mix at least one of the transmitted RF signals with at least one of the reflected RF signals to generate a modified signal;   an analog-to-digital converter configured to convert the modified signal into digital data thereby providing a digital representation of said modified signal;   at least one processor for processing digital data;   wherein said handheld structure contains said frequency controlled oscillator, said at least one antenna; and said mixer; said analog-to-digital converter, and said at least one processor; and   wherein said system is configured to use said digital representation of said modified signal and a model relating said modified signal to arterial blood pressure, to generate an arterial blood pressure signal indicating arterial blood pressure of the user as a function of time; and   wherein said at least one antenna comprises a first antenna and a second antenna, said first antenna is located in said handheld structure relative to an artery in a left hand of the user so that it senses arterial diameter when said system is held in the left hand of said user, and said second antenna is located in said handheld structure relative to an artery in a right hand of the user so that it senses arterial diameter when said system is held in the right hand of said user.   
     
     
         6 . The system of  claim 1  wherein said system is configured to transmit said arterial blood pressure signal indicating arterial blood pressure of the user as a function of time over a cellular network. 
     
     
         7 . The system of  claim 1  further comprising a heart rate determination algorithm designed to determine heart rate of a user, wherein said heart rate determination algorithm is designed to determine heart rate of a user from said digital representation of said modified signal and at least one model function for heart rate, wherein said algorithm is implemented in at least one of software and hardware. 
     
     
         8 . The system of  claim 1  comprising said handheld mechanical housing and wherein said handheld mechanical housing contains said frequency controlled oscillator; said at least one antenna; and said mixer, and a transceiver designed to wirelessly communicate with said handheld device. 
     
     
         9 . The system of  claim 8  comprising both said handheld mechanical housing and said handheld device; and
 wherein said handheld mechanical housing contains said frequency controlled oscillator, said at least one antenna, said mixer, and a low power transceiver designed to wirelessly communicate with said handheld device. 
 
     
     
         10 . The system of  claim 9  wherein said low power transceiver is designed to transmit in at least one of the following frequency bands: 6.765 to 6.795 MHZ; 13.553 to 13.567 MHZ; 26.957 to 27.283 MHZ; 40.660 to 40.700 MHZ; 433.050 to 434.790 MHZ; 902.000 to 928.000 MHZ; 2.400 to 2.500 GHz; 5.725 to 5.875 GHz; 24.000 to 24.250 GHz; 61.000 to 61.500 GHz; 122.000 to 123.000 GHz; and 244.000 to 246.000 GHz. 
     
     
         11 . The system of  claim 9  wherein said low power transceiver is configured to transmit either said modified signal or said digital representation of said modified signal to said handheld device, when said handheld device is removably mechanically clamped or latched onto or contained in said handheld mechanical housing. 
     
     
         12 . The system of  claim 1  wherein said system is designed to estimate distance of the antenna or antennas from the skin using the amplitude and phase of the signal reflected from skin, and to compensate determination of arterial blood pressure based upon there upon. 
     
     
         13 . The system of  claim 5  wherein said handheld structure has a relatively long dimension, a first end along said relatively long dimension, a second end along said relatively long dimension, said first antennae is disposed closer to said first end than said second end, and said second antennae is disposed relatively closer to said second end than said first end. 
     
     
         14 . The system of  claim 1  further comprising an elliptical disk at a termination of said feed line adjacent said slot. 
     
     
         15 . The system of  claim 1  further comprising:
 a bottom dielectric sheet and a top dielectric sheet stacked upon one another; 
 wherein metal defining said slot resides on a top surface of said top dielectric; 
 wherein said feed line resides beneath said top dielectric sheet; and 
 further comprising a detector diode located on said top dielectric sheet. 
 
     
     
         16 . A method for determining arterial blood pressure of a user as a function of time, comprising:
 powering with a battery, a handheld structure comprising at least one of: (1) a handheld device configured to be held in one hand of a person comprising a cellular telephone transceiver and human interface; and (2) a handheld mechanical housing configured to be held in one hand of the person, and designed to removably mechanically clamp or latch onto a handheld device; a frequency controlled oscillator to generate RF signals; at least one antenna configured to transmit the RF signals generated by the frequency controlled oscillator and configured to receive RF signals which are reflections of the transmitted RF signals; a mixer configured to mix at least one of the transmitted RF signals with at least one of the reflected RF signals to generate a modified signal; an analog-to-digital converter configured to convert the modified signal into digital data thereby providing a digital representation of said modified signal; at least one processor for processing digital data; wherein said handheld structure contains said frequency controlled oscillator; said at least one antenna; and said mixer, said analog-to-digital converter; and said at least one processor; and   using said digital representation of said modified signal and a model relating said modified signal to arterial blood pressure, to generate an arterial blood pressure signal indicating arterial blood pressure of the user as a function of time;   wherein said at least one antenna defines a slot;   coupling said the RF signals generated by the frequency controlled oscillator to said antenna via a feed line in the form of a conductive layer,   controlling said frequency controlled oscillator to generate said RF signals in pulses at a repetition rate, and said repetition rate is sufficiently above the heart rate to provide reflection signal data points allowing curve fitting the reflection signal data to form a useful approximation for periodic variations in artery diameter at the periodicity of the heart rate   controlling said frequency controlled oscillator to generate said RF signals in a frequency range between 3.1 and 10.6 GHz and with a subband of bandwidth of at least 500 MHz;   wherein said RF signals generated by the frequency controlled oscillator have peak power between 1 uW and 100 mW peak, and average power between 1 uW (microWatt) and 10 mW (milliWatt); and   wherein said battery provides power to said frequency controlled oscillator.   
     
     
         17 . The method of  claim 16  further comprising determining heart rate of a user, using a heart rate determination algorithm designed to determine heart rate of a user, wherein said heart rate determination algorithm is designed to determine heart rate of a user from said digital representation of said modified signal and at least one model function for heart rate, wherein said algorithm is implemented in at least one of software and hardware. 
     
     
         18 . A system for determining arterial blood pressure of a user as a function of time, comprising:
 a handheld structure comprising at least one of: (1) a handheld device configured to be held in one hand of a person comprising a cellular telephone transceiver and human interface; and (2) a handheld mechanical housing configured to be held in one hand of the person, and designed to removably mechanically attach or clamp onto a handheld device;   a frequency controlled oscillator to generate Radio Frequency (RF) signals;   at least one antenna configured to transmit the RF signals generated by the frequency controlled oscillator and configured to receive RF signals which are reflections of the transmitted RF signals;   a mixer configured to mix at least one of the transmitted RF signals with at least one of the reflected RF signals to generate a modified signal;   an analog-to-digital converter configured to convert the modified signal into digital data thereby providing a digital representation of said modified signal;   at least one processor for processing digital data; and   wherein said at least one antenna comprises a first antenna and a second antenna, said first antenna is located in said handheld structure relative to an artery in a left hand of the user so that it senses arterial diameter when said system is held in the left hand of said user, and said second antenna is located in said handheld structure relative to an artery in a right hand of the user so that it senses arterial diameter when said system is held in the right hand of said user.   
     
     
         19 . The system of  claim 18  wherein metal forming said first antenna and said second antenna are disposed on the same surface of a dielectric substrate. 
     
     
         20 . The system of  claim 18  further comprising an antenna selection switch coupled to said mixer, said first antenna, and said second antenna, wherein said antenna selection switch is controlled by said at least one processor.